After more than a decade on the FBI's "Ten Most Wanted Fugitives" list, Fisher has yet to be apprehended. But the 15-year anniversary, coupled with recent media coverage, has fueled a slew of new tips that investigators say might finally lead to his capture.
"There have been a ton of tips," says FBI Supervisory Special Agent Lance Leising, who is working the case. "It's not known yet if any of those tips will be promising. But we follow the facts, so we don't dismiss anything."
Most recently, the FBI has returned to the roots of the investigation in order to freshly view the case.
"We've gone back to the very beginning, where it all started," Leising ays. "We've gone back and scrubbed the case — every interview, every report that was done, every item of evidence that was found. And we start with each one to see if there is anything we've glossed over or missed. So we're working on that now."
The Fisher case began on April 10, 2001, when a firefighters responded to reports of a Scottsdale house fire. Combing through the charred remains of the home, investigators made a shocking discovery.
Robert Fisher's wife, Mary Fisher, 38, was discovered with her throat slit and a gunshot wound in the back of the head. Their daughter Britney, 12, and son Bobby, 10, had their throats slit from ear to ear. Their bodies were so badly burned, they were barely recognizable. All three were found in their beds.
Clues pointed to the Scottsdale husband and father, Robert Fisher, who, friends told investigators, was aggressive, controlling, and in an unhappy marriage.
Before fleeing the scene, investigators say, Fisher severed a gas line in the home, poured flammable liquid throughout the property, and lit a candle, causing the house to explode and burn to the ground.
Neighbors would report having heard an argument on the night of the murders, which police estimate took place April 9, 2001, between 9:30 and 10:15 p.m.
At 10:43 p.m. that night, Robert Fisher, a respiratory tech at a medical clinic and an avid hunter and outdoorsman, appeared on an ATM camera, with Mary Fisher's Toyota 4Runner in the background. Ten days later, the 4Runner was discovered abandoned in a remote pine forest in northern Arizona.
Police suspected Robert Fisher was hiding out in the area's mountains, canyons, and caves. Search teams scoured the area but found no sign of Fisher, leading to a lingering mystery: Was he dead or alive?
If he is alive today, Fisher would be 55. He's six feet tall, and when last seen he weighed 190 pounds and wore his hair closely cropped. Investigators say he may bear little resemblance to the Robert Fisher of 2001, and the FBI has created multiple photo-illustrations that demonstrate how Fisher's appearance might have changed.
While much of the public has thought he was dead, the FBI is working under the theory he is very much alive.
"There are several theories," Leising says. "It is a theory that he is living off the grid. There's theories that he's living with someone but changed his identity, name, and background."
Mary Fisher's family still lives in Arizona and remain involved in the investigation, Leising says.
"We work these cases for the victims," says Leising. "The FBI doesn't forget. We're gonna keep him on this 'Top Ten' list till we feel like we've exhausted all means to find him, or prove he's dead."